2020 贝壳笔试题——最小增加总和

#include 
#include 
#include 
#include 
#include

using namespace std;

int main() {
   int n;
   cin >> n;
   vector temp(n);
   if (n == 1)
      cout << 0 << endl;
   for (int i = 0; i < n; i++) {
      cin >> temp[i];
   }
   int sum = 0, left = 0, right = n - 1;
   while (left < n && temp[left] < temp[left + 1]) {
      left++;
   }
   while (right >= 0 && temp[right] < temp[right - 1]) {
      right--;
   }
   if (left + 1 >= right) {
      if (temp[left] == temp[right] && left != right) {
         cout << 1 << endl;
      }
      else {
         cout << 0 << endl;
      }
      return 0;
   }
   while (left + 1 < right) {
      if (temp[left] < temp[right]) {
         int need = temp[left] - temp[left + 1] + 1;
         sum += need;
         temp[left + 1] += need;
         left++;
      }
      else {
         int get = temp[right] - temp[right - 1] + 1;
         sum += get;
         temp[right - 1] += get;
         right--;
      }
   }
   if (temp[left] == temp[right]) {
      sum++;
   }
   cout << sum;
   return 0;
}